The present invention relates to a new and improved method and apparatus for casting a metal article. A heater, which may be referred to as an auxiliary or secondary furnace, is utilized to transmit heat to a mold after the mold has been removed from a first or main furnace.
A known apparatus includes a mold having a pour cup. Molten metal is conducted from the pour cup through feeder passages to an article mold cavity. A heating coil is wrapped around a portion of the feeder passages. During and after pouring of molten metal into the pour cup, heat is provided by the heating coil to maintain metal in the feeder passages molten. An apparatus having this construction is disclosed in U.S. Pat. No. 3,752,221.
Another known apparatus is disclosed in U.S. Pat. No. 1,789,883. This patent discloses a hot-top which is positioned on an ingot mold. Electrical resistance wires are provided in the hot-top. Various hot-top constructions are also disclosed in U.S. Pat. Nos. 1,074,251; 1,933,530; 2,229,507; and 3,630,480.